Tuesday, August 01, 2017

Time travel is a more or less ubiquitous feature of modern sci-fi. Almost every long running SF show – Star Trek, Futurama, The X-Files – will have a time travel episode sooner or later, and some, like Doctor Who, use time travel as the main narrative device. The same applies to novels and, of course, to Hollywood – blockbuster SF franchises like the Terminator and Back to the Future employ it, as do quirkier pictures like Midnight in Paris. And of course, there’s no shortage of time travel novels, including old favorites like A Christmas Carol, and perhaps most influentially, HG Wells’s wonderful social sci-fi novella The Time Machine.

I don’t find it particularly surprising that we’re so interested in time travel. We all engage in so called ‘mental time travel’ (or Chronaesthesia) all the time, reviewing past experiences and imagining possible futures, and the psychological capacities required in our doing so are the subject of intense scientific and philosophical interest.

Admittedly, the label “mental time travel” may be a bit misleading here; most of what gets labelled mental time travel is quite different from the SF variant, consisting in episodic recall of the past or projection into the future rather than imagining our present selves thrown back in time. But I think we also do this latter thing quite a lot. To give a commonplace example, we’re all prone to engage in “coulda woulda shoulda” thinking: if only I hadn’t parked the car under that tree branch in a storm, if I only I hadn’t forgotten my wedding anniversary, if only I hadn’t fumbled that one interview question. Frequently when we do this, we even elaborate how the present might have been different if we’d just done something a bit differently in the past. This looks a lot like the plots of some famous science fiction stories! Similarly, I’m sure we’ve all pondered what it would be like to experience different historical periods like the American Revolution, the Roman Empire, or the age of dinosaurs (you can even buy a handy t-shirt). More prosaically, I imagine many of us have also reflected on how satisfying it would be to relive some of our earlier life experiences and do things differently the second time round – standing up to high school bullies, or studying harder in high school (again, a staple of light entertainment).

Given the above, I had always assumed that time travel was part of fiction because it was simply part of us. Time travel narratives, in other words, were borrowed from the kind of imaginings we all do all the time. It was with huge surprise, then, that I discovered (while teaching a course on philosophy and science fiction) that time travel doesn’t appear in fiction until the 18th century, in the short novel “Memoirs of the Twentieth Century”. Specifically, this story imagines letters from the future being brought back to 1728. The first story of any kind (as far as I’ve been able to find) that features humans being physically transported back into the past doesn’t come until 1881, in Edward Page Mitchell’s short story “The Clock That Went Backwards”.

Maybe this doesn’t seem so surprising – isn’t science fiction in the business of coming up with bizarre, never before seen plot devices? But in fact, it’s pretty rare for genuinely new ideas to show up in science fiction. Long before we had stories about artificial intelligence, we had the tales of Pinocchio and the Golem of Prague. Creatures on other planets? Lucian's True History had beings living on the moon and sun back in the 2nd century AD. For huge spaceships, witness the mind-controlled Vimanas of the Sanskrit epics. And so on. And yet, for all the inventiveness of folklore and mythology, there’s very little in the way of time travel to be found. The best I’ve come up with so far is some time dilation in the stories of Kakudmi in the Ramayanas, and visions of the past in the Book of Enoch. But as far as I can tell, there’s nothing that fits the conventional time travel narratives we’re used to, namely physically travelling to ages past or future, let alone any idea that we might alter history.

What’s going on here? One possibility is that something changed in science or society in the 18th century that paved the way for stories about time travel. But what would that be, and how would it lead to time travel seeming more plausible? For example, if the first time travel literature had accompanied the emergence of general relativity (with all its assorted time related weirdness), then that would offer a satisfying answer. However, Newtonian physics was already in place by the late 17th century, and it’s not clear which of Newton’s principles might pave the way for time travel narratives.

I’m very open to suggestions, but let me throw out one final idea: time travel narratives don’t show up in earlier fiction because they’re weird, unnatural, and counterintuitive. Even weirder than the staples of folklore and mythology, like people being turned into animals. Time travel is just not the kind of thing that naturally occurs to humans to think about at all, and it’s only via a few fateful books in the 18th century and its subsequent canonisation in The Time Machine that it’s become established as a central plot device in science fiction.

But doesn’t that contradict what I said earlier about how we all often naturally think about time travel related scenarios, like changing the past, or witnessing historical events firsthand? Not necessarily. Maybe these kinds of thought patterns are actually inspired by time-travel science fiction. In other words, prior to the emergence of time travel as a trope, maybe people really didn’t daydream about meeting Julius Caesar or going back and changing history. Perhaps the past was seen simply as a closed book, rather than (in the memorable words of L. P. Hartley) just “a foreign country”. That’s not to suggest, of course, that people didn’t experience memories and regrets, but maybe they experienced them a little differently, with the past seeming simply an immutable background to the present.

I’m excited the idea that a science fiction trope might have birthed a new and widespread form of thinking. Partly that’s because it suggests that science fiction may be more influential than we realize, and partly it’s because, as a philosopher, I’m interested in where patterns of thought come from. However, I’m very happy to proven wrong in this conjecture – perhaps there are letters from the Middle Ages in which writers engage in precisely this kind of speculation. Or perhaps the emergence of science fiction in the 18th century can be explained in terms of some historical event I’ve missed. Or who knows: maybe there’s an untranslated gnostic manuscript out there where Jesus has a time machine....

While it isn't a true time-travel scenario, many of the issues of free-will vs. predestination that are dealt with in time-travel stories were hashed out in stories about oracles-- for example, Oedipus Rex.

The earliest reference I know to time as a "fourth dimension" in which one could travel forward and backward is Lagrange's Theory of Analytic Functions from 1797. Perhaps the idea originated with math and gradually spread to literature? The Time Machine by H G Wells discusses time as a fourth spatial dimension this way.

I think it's because the concept of progress, understood macroscopically, lacked currency. We could perfect ourselves - become virtuous etc - and we could perfect society. But, these involve an anthropological or geographical imaginary: we go somewhere different where people are different. But, the more fundamental order of things remains the same.

Time travel presupposes that the future is not just a different place but different in ways that are geographically inaccessible. Another way to put it: people need to be able to think of the geographically accessible, i.e. the local, as potentially wildly mysterious. What adds the deep mystery is the passage of time.

That is, one has to think of the world as changing in ways that transform the deeply familiar into the deeply unfamiliar. The cast of characters does not change; rather everything *else* changes even while many in the cast of characters could stay the same (e.g., we can have the same character tropes, as Asimov famously has in his hardboiled I Robot books).

So, a transformation that occurred that facilitated thinking about time travel is a transformation in how we thought about progress.

Like all journeys, traveling in time requires a destination – a past and/or future time to visit. Which means that time travel is inconceivable unless everything we consider past and future persists (or perdures) so that the past, present and future are permanently existing spacetime destinations that can be visited repeatedly.

Fortunately for lovers of time travel stories, myself included, that's how our own universe is constructed – we live in a 4-dimensional Block Universe (BU) of Minkowski spacetime. That our universe is a BU was firmly established on scientific grounds in 1905 with the publication of Einstein's Special Theory of Relativity (STR) as a consequence of the relativity of simultaneity. [To learn more about the relativity physics involved, consult one of these three lucid, general audience descriptions of the BU and the relativity of simultaneity: Brian Greene in The Fabric of the Universe (chapter 3), Paul Davies in About Time (chapter 2), and Lee Smolin's description in Time Reborn (chapter 6)].

Physicist Robert Geroch characterizes the BU perspective in physics as follows:

“Physicists prefer to think of time as laid out in its entirety - a timescape, analogous to a landscape - with all past and future events located there together.”

While the unchanging BU has only been grounded in physics for a bit over a century, it's a very old philosophical idea known as Eternalism. For example, from Parmenides:

“There remains, then, but one word by which to express the [true] road: Is. And on this road there are many signs that What Is has no beginning and never will be destroyed: it is whole, still, and without end. It neither was nor will be, it simply is-now, altogether, one, continuous ...”

Perhaps the earliest science fiction time travel plots were influenced by this philosophical idea, which has emerged repeatedly in the history of philosophy. I'm unaware of any 18th century philosophical or scientific developments that might have “paved the way for stories about time travel,” but in the late 19th century the scientific idea of the BU began to appear in print.

In your post, Henry, you wrote that “humans being physically transported back into the past doesn’t come until 1881”. Interestingly enough, in that time frame, in an 1880 article, “What is the Fourth Dimension,” British scientist Charles Hinton imagines “... some stupendous whole, wherein all that has ever come into being or will come coexists.” Perhaps there's a connection.

A few years beyond that, in the early 20th century and subsequent to Einstein's STR in 1905, mathematician Hermann Minkowski introduced his 4-dimensional spacetime geometry in 1908: “Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.” Dating from those years, the idea of human time travel perhaps became more imaginable and less “weird, unnatural, and counterintuitive” and evolved into acceptable “thought patterns”. So that, by 1969, Kurt Vonnegut's Tralfamadorians of Slaughterhouse Five are able to directly perceive the BU. Per Billy Pilgrim:

“All moments, past, present and future, always have existed, always will exist. The Tralfamadorians can look at all the different moments just the way we can look at a stretch of the Rocky Mountains, for instance. They can see how permanent all the moments are, and they can look at any moment that interests them. It is just an illusion we have here on earth that one moment follows another like beads on a string, and that once a moment is gone it is gone forever.”

One avenue that might be worth exploring here is the history of the concept of time, or even more broadly, the history of the way people understood time should *concepts* be too stifling a medium.

Consider that the ancient Greeks had a word, καιρός, which marked off a qualitative aspect to time. We moderns take it for granted that time just is the sequential ordering of events, which may or may not be tensed depending on your preferred theory of time; but the linear, quantitative "spatializing" of time is all but taken for granted.

Charles Taylor's A SECULAR AGE traces some of the ramifications of the loss of this qualitative aspect of time. Time, conceived as a part of the physical world now purged of divinely-authored meanings, becomes one more quantity to formalize and bring under the auspices of human will and knowledge.

It may well be that we didn't see time travel stories prior to the Industrial Revolution because, before then -- complete with the trend towards rigorous scheduling of lives around work-days -- people simply didn't conceive of "past" and "future" in the way that is now backed into our latter-day common sense.

We think of time as ticks on the clock, marching from future to past to be forever lost. We moderns and post-moderns in the West are also fairly peculiar in this, by all accounts. If the conceptual scheme (and again even putting it this way shows a certain bias towards quantification) built into our ways of talking about time is rigged so that time travel becomes -- let's not say conceivable, but something which can occupy the imagination -- then we shouldn't be surprise that the artistic mode is a product of a historically and culturally unusal way of conceiving the subject.

Is the Book of Revelation a time travel story? John of Patmos presumably time travels to the end of history, no? It may be more of a La Jetée-style time travel in which only John's consciousness was transported, but it does have John "seeing" events that will take place in the future (and some allegorical visions of the past too? The bit with the woman and dragon is ambiguous about when it is happening).

For anyone still monitoring this thread, or Googlers who might land here someday, I've just finished reading James Gleick's 2016 book "Time Travel - A History". A most entertaining and informative read. I believe Henry's question gets a thorough treatment.

Just because there are no fictional narratives about Time Travel before the eighteenth century doesn't mean that earlier writers didn't imagine it. Perhaps one reason why we seem unable to find examples of traditional time travel narratives (as in novels or drama) prior to the eighteenth century is because the notion of time as chronological and teleological was a fairly new one, a post-cartesian idea that developed roughly around the same time as the modern, third person omniscient novel. The middle ages and the early modern period had very different, much less linear concepts of time.

Shakespeare has several references to Time Travel in his plays and poetry. Sonnet 59 imagines that the beloved either lived and died in the past, or somehow traveled back there. And Hamlet, fooling around in his antic disposition (and no doubt wishing deeply he could undo what happened to his father) imagines time running backwards, when he tells Polonius that "you yourself should be as young as I am, if like a crab you could go backwards." John Donne, in his amazing poem "The Relic" projects himself forward in time to the moment of burial, wishing to be buried with a bracelet of his beloved's hair, and then imagines a future where the two are dug up and worshipped as relics.

Renaissance writers, musing on the surge of interest in ancient Greece and Rome that defined their own epoch, often imagined themselves traveling back to ancient Rome. The unearthing of pristine embalmed ancient bodies in Rome aided such fantasies. Petrarch imagines talking across time to numerous illustrious Roman writers, and Gabriel Harvey used to dress up as his favorite classical writers and attempt to recreate Roman banquets.

I guess what I'm saying is that the genre of time travel as "genre fiction" that we know and recognize may have not existed before the eighteenth-century, but that literature has been imagining types of time travel long before that.

And all that said, I'm still looking for an obscure Renaissance play, narrative poem, or prose romance that depicts a character going back in time. Because I would love to write about it.